I am writing to you today because I need help with one of my fish. I do not know exactly what he has. I thought it was ich so I treated him for 4 days with mardel quick cure. It seemed to be okay when I transferred him back to the main tank. He has a great appetite and it is eating well but his body and the way he swims suggest that he is sick. I am not sure if it is still ich. Can you please help me in understanding what is going on? You can see a video of the fish here: